This invention relates to the production of epoxy silicate foams by the chemical reaction of an inorganic oxidated silicon compound with an organic amine compound and an epoxy compound. The product produced by this invention will be referred to as epoxy silicate foam for the purpose of this application.
Various inorganic silicates and related oxidated silicon compounds such as silicoformic acid, hydrated silica, and silicates containing free silicic acid groups may be used in this invention. It is preferred that the inorganic silicates, silicon dioxide, silica, hydrated silica, and mixtures thereof be in the form of a fine granular or powdered compound.
The silicoformic acid may be produced by the methods of U.S. Pat. Nos. 3,956,466, 3,993,737, and 3,962,111.
The silica (SiO.sub.2) and hydrated silica (SiO.sub.2.H.sub.2 O) may be produced by any of the commonly known methods. Hydrated silica may be produced by reacting an acid with an aqueous solution of sodium silicate, thereby producing a silicic gel which is then dried thereby forming a hydrated silica.
Any suitable inorganic silicate may be used in this process. Silicates, containing free silicic acid groups are preferred. Many of the common silicates may be used in this process such as clay, talc, alkali metal silicates, alkaline earth metal silicates, zeolite, magnesium silicate, diatomaceous earth, soapstone, tremoline, feldspar, kaolin and other silicates.
The epoxy silicate foam may be produced as rigid foams, semirigid foams, soft foams, and rubbery soft foams. The foams may be expanded from 3 to 10 times the original liquid volume. The epoxy silicate foams have a number of diverse applications. They may be molded into useful foam objects. They may be foamed in place. They may be used for insulation, floatation, strengthening material and packaging material. The epoxy silicate foams may be produced in the form of a soft foam which can be used as a packaging material to protect fragile objects and is biodegradable. It disintegrates when it becomes wet unless modified by additives.